The subject matter disclosed herein relates to airfoils. More specifically, the subject disclosure relates to airfoils utilized in aircraft engines and propeller-driven craft, including aircraft and land/watercraft.
In an effort to decrease weight of parts having an airfoil shape, such as aircraft engine fan blades, exit guide vanes, propeller blades for aircraft and land/watercraft, and certain structural support members located in airstreams, the use of composite components, such as graphite fiber reinforcements with an epoxy matrix, in such parts has increased. Parts having composite components at their edges (e.g., leading edges, trailing edges, and tips) do not exhibit adequate strength or hardness to protect themselves from erosion and foreign object damage, and especially from damage as a result of impact with birds, ice, stones, sand, rain and other debris. Accordingly, protective sheaths are often used to protect the parts.
The typical sheath, however, is permanently affixed to the part, and therefore the service life of the part is limited by the life of the sheath. In the event of erosion of, or damage to the sheath, the part must be replaced.